Lately my studies have been focusing on learning the machinery of K-Theory, and I thought that learning the Atiyah-Singer Index Theorem would be a good way to see K-Theory in action a bit and to learn a deep result on the way. From what I have read, there are a few methods of proof of Atiyah-Singer, one of which uses K-Theory. Also from what I have read, it seems that I have most of the background knowledge to approach the proof of Atiyah-Singer.

However, it doesn't seem that there is a standard reference or sequence of references to go to in order to learn the proof of this theorem. In particular, I am not sure which book(s) would be best to look at to see a proof of Atiyah-Singer which utilizes K-Theory. I have found a few that seem to take the K-Theory approach to the theorem, but I have no way of telling how good or useful they are.

So what I am asking for is a roadmap or a reference to a proof of the Atiyah-Singer Index Theorem that uses K-Theory, and of course other advice concerning learning this theorem is welcome as well.